Man its been awhile since last posted, we have been very busy. We landed a fleet contract of 53 foot chip (sawdust) vans. Some of these older vans have not been washed on a frequent basis and have a permenant stain about half the way up and the entire length caused by road spray. Have tried several things and have peeled some of this stain off, but not completely. Have used 2 step, several detergents. This is old paint and I'm not convinced this will every come completely clean. Any suggestions?